Overmolded Plastic Pipe Branch for Gas-Tight Sealing

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Solution Overview

Problem

Existing gas-tight plastic pipe connections, such as welding and gluing, are prone to defects and leaks due to the complexity and inefficiency of current methods, particularly in applications like filling valves and pressure sensors.

Innovation Solution

A gas-tight plastic pipe branch design featuring a first pipe section with a branch bore and a second pipe section with a tubular shoulder and sealing element, where the sealing element is clamped between the pipe sections and overmoulded with plastic, eliminating the need for welding or gluing and enhancing security with an anchoring element and shrinkage-induced encapsulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If reinforcing supports are welded onto pipes to prevent premature failure, then connection strength is improved, but the complexity and risk of welding defects increase

Engineering Contradiction:
Improveconnection strengthVSAvoidwelding complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent combines the functions of connection, reinforcement, and gas-tight sealing into a single integrated press-fit mechanism. The expansion element simultaneously provides structural reinforcement, mechanical locking, and gas-tight sealing without requiring separate welding operations or additional reinforcing components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent removes the need for separate reinforcing supports that would require welding. The second pipe section itself, when expanded, becomes the reinforcing element, eliminating the need for additional reinforcing components and their associated welding operations.

Inventive Principle:
Principle #2Taking out (Extraction)

2Adaptability or versatility

If additional components are added to create a branch connection, then connection functionality is improved, but the risk of leaks at adhesive joints increases

Engineering Contradiction:
Improvebranch connection functionalityVSAvoidleak risk
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent integrates the branch connection functionality directly into the pipe wall structure through a receptacle formed in the first pipe section. This eliminates the need for separate adhesive joints between components, as the branch connection is formed as an integral part of the pipe structure with a single press-fit operation ensuring gas tightness.

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If a complex device is used to expand a sleeve in a pipe, then secure connection is achieved, but the device is cumbersome to operate

Engineering Contradiction:
Improveconnection securityVSAvoiddevice operation
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent employs a self-expanding mechanism where the second pipe section expands automatically upon insertion into the first pipe section. The expansion is driven by the insertion force itself, eliminating the need for external mandrels or complex expansion devices. The second pipe section serves its own function as both the connection element and the expansion element.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design ensures a secure, gas-tight connection with high form-fitting security and resistance to unintentional loosening, addressing the issues of leaks and complexity in existing methods.

Implementation Method 1

the plastic material of the overmolding exhibits a predetermined shrinkage upon cooling

Methodology Applied
Scientific EffectShrinkage: Thermal Contraction

Data Source

PatentEP3382253B1Gas-tight plastic pipe branch
Publication Date: 2023.04.12 CONTITECH TECHNO CHEMIE GMBH
  • EP3382253B1 patent drawingFigure 1

AI summary

The invention relates to a gas-tight plastic pipe branch (1) comprising a first pipe section (2) and a second pipe section (5). The invention was based on the objective of modifying a pipe branch of the described type in such a way that a reliable gas-tight connection at the branch point is ensured. This objective is achieved by: - ​​the first pipe section (2) having a branch bore (4); and - the second pipe section (5) having a tubular shoulder (6) with an end contour (8), wherein the end contour (8) can be inserted into the branch bore (4) of the first pipe section (2) and has a receptacle for a sealing element (9); and - a sealing element (9) being arranged in the receptacle of the end contour (8) of the second pipe section (5).wherein the sealing element (9) comes to lie in the branch bore (4) of the first pipe section (2) between the first pipe section (2) and the second pipe section (5) when the contour (8) of the second pipe section (5) is inserted, and the first and second pipe sections (2, 5) with tubular shoulder (6) and sealing element (9) are substantially completely overmolded with a plastic material (10) in a predetermined area around the branch.